Characterization of AIDS virus isolated and their growth in permissive cells is currently underway. New cell lines are being evaluated for their capability in becoming infected with and producing human retroviruses suspected as the cause of AIDS. Analysis of the viruses will be accomplished by western blot or ELISA with AIDS patients sera and heterologous or monoclonal antibody currently being produced. Other investigations underway are those of understanding the cellular biology of the growth of the viruses in both normal human T cells and tumor cell lines. These studies utilize reverse transcriptose detection FACS analysis, and cellular morphology as methods of evaluation. Development of CPE and neutralization assays are also being investigated in order to study the cellular biology of these viruses.